John Dalton

Wednesday, November 11, 2009

photo: uh.edu

John Dalton was an English physicist, meteorologist and chemist expert, pioneering work in the development of modern atomic theory, and his research into color blindness (sometimes referred to as Daltonism, in his honour), atomic sign, double proportion law, dalton law, atomic sign, founder of rain cause, author, teacher, and Royal Society member. He never married because never have time for that. Born at Eaglesfield, near Cockermouth in Cumberland, England on September 6, 1766 and dies in Manchester on July 27, 1844 at 78 years old. Because founded atomic theory by scientist not theory likes Democritus that based on philosophy and speculative so Dalton mention as atomic theory father. His father was weaver and has six children. Dalton father is poor that why he can school their child till high school. At 11 years old, Dalton must drop out from school and must looked jobs for him. Dalton and his father were Quaker. Quaker or Friend is a religious movement. Most groups of Friends meet for regular worship, but the form this takes differs considerably between different Yearly Meetings and traditions, ranging from silent meetings with no leader and no fixed plan of what will happen, through to services led by a pastor with readings and hymns (similar to conventional church services). Dalton was humble child and like learning by himself so he clever than another children at his age. In the night he learn math. At 12 years old he became teacher. But his salary was very small only 5 shilling in one week. Two year later he was looking a new job. He got job as farm worker. But this job obviously not matched with he wish. At 15 years old, he became teacher again at Kendal till he got headmaster position at 27 years. Later he moved to Manchester. In this city he met John Gough, a blind philosopher and polymath from whose informal instruction he owed much of his scientific knowledge, Dalton was appointed teacher of mathematics and natural philosophy at the "New College" in Manchester, a Dissenting academy. Dalton stared interesting to meteorologist since 12 yeas old. Starting at that age till he dies, Dalton recorded his observation. For 57 years he recorded 200,000 observations. At 27 years old, his first book Meteorological Observations and Essays (1793) published, which contained the seeds of several of his later discoveries. A second work by Dalton, Elements of English Grammar, was published in 1801. Although Dalton's theory lost credence in his own lifetime, the thorough and methodical nature of his research into his own visual problem was so broadly recognized that Daltonism became a common term for color blindness. Examination of his preserved eyeball in 1995 demonstrated that Dalton actually had a less common kind of color blindness, deuteroanopia, in which medium wavelength sensitive cones are missing (rather than functioning with a mutated form of their pigment, as in the most common type of color blindness, deuteroanomaly). Besides the blue and purple of the spectrum he was able to recognize only one color, yellow, or, as he says in his paper,

that part of the image which others call red appears to me little more than a shade or defect of light. After that the orange, yellow and green seem one colour which descends pretty uniformly from an intense to a rare yellow, making what I should call different shades of yellow.